FeMBMS 1.25KHz Pilots (MBSFN Gold psequences)

openair1/PHY/LTE_REFSIG/lte_dl_mbsfn.c

@@ -154,3 +154,92 @@ int lte_dl_mbsfn_rx(PHY_VARS_UE *ue,
   return(0);
 }
 
+#if (LTE_RRC_VERSION >= MAKE_VERSION(14, 0, 0))
+int lte_dl_mbsfn_khz_1dot25(PHY_VARS_eNB *eNB, int32_t *output,
+                 short amp,
+                 int subframe) 
+{
+
+  unsigned int mprime,mprime_dword,mprime_qpsk_symb,m;
+  unsigned short k=0,a;
+  int32_t qpsk[4];
+
+  a = (amp*ONE_OVER_SQRT2_Q15)>>15;
+  ((short *)&qpsk[0])[0] = a;
+  ((short *)&qpsk[0])[1] = a;
+
+  ((short *)&qpsk[1])[0] = -a;
+  ((short *)&qpsk[1])[1] = a;
+  ((short *)&qpsk[2])[0] = a;
+  ((short *)&qpsk[2])[1] = -a;
+
+  ((short *)&qpsk[3])[0] = -a;
+  ((short *)&qpsk[3])[1] = -a;
+
+
+  mprime = 3*(110 - eNB->frame_parms.N_RB_DL);
+
+  for (m=0; m<eNB->frame_parms.N_RB_DL*24; m++) // m = 0:24*N_RB_DL-1
+  {
+      if ((subframe&0x1)==0) // n_sf mod 2 == 0: even 
+        k = 6*m;
+      else
+        k = 6*m + 3;
+
+
+      k+=eNB->frame_parms.first_carrier_offset_khz_1dot25;
+
+      mprime_dword     = mprime>>4;
+      mprime_qpsk_symb = mprime&0xf;
+
+      if (k >= eNB->frame_parms.ofdm_symbol_size_khz_1dot25) {
+        k++;  // skip DC carrier
+        k-=eNB->frame_parms.ofdm_symbol_size_khz_1dot25;
+      }
+      output[k] = qpsk[(eNB->lte_gold_mbsfn_khz_1dot25_table[subframe][mprime_dword]>>(2*mprime_qpsk_symb))&3];
+      mprime++;
+   }
+
+  return(0);
+}
+
+
+int lte_dl_mbsfn_khz_1dot25_rx(PHY_VARS_UE *ue,
+                    int *output,
+                    int subframe) 
+{
+
+  unsigned int mprime,mprime_dword,mprime_qpsk_symb,m;
+  unsigned short k=0;
+  unsigned int qpsk[4];
+
+  // This includes complex conjugate for channel estimation
+
+  ((short *)&qpsk[0])[0] = ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[0])[1] = -ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[1])[0] = -ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[1])[1] = -ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[2])[0] = ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[2])[1] = ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[3])[0] = -ONE_OVER_SQRT2_Q15;
+  ((short *)&qpsk[3])[1] = ONE_OVER_SQRT2_Q15;
+
+  mprime = 3*(110 - ue->frame_parms.N_RB_DL);
+
+  for (m=0; m<ue->frame_parms.N_RB_DL*24; m++) // m = 0:24*N_RB_DL-1
+  { mprime_dword     = mprime>>4;
+    mprime_qpsk_symb = mprime&0xf;
+
+    // this is r_mprime from 3GPP 36-211 6.10.1.2
+    output[k] = qpsk[(ue->lte_gold_mbsfn_khz_1dot25_table[subframe][mprime_dword]>>(2*mprime_qpsk_symb))&3];
+
+    mprime++;
+    k++;
+
+  }
+
+  return(0);
+}
+
+#endif // MAKE Rel14
+

openair1/PHY/LTE_REFSIG/lte_gold_mbsfn.c

@@ -95,6 +95,34 @@ void lte_gold_mbsfn(LTE_DL_FRAME_PARMS *frame_parms,uint32_t lte_gold_mbsfn_tabl
 }
 
 
+#if (LTE_RRC_VERSION >= MAKE_VERSION(14, 0, 0))
+void lte_gold_mbsfn_khz_1dot25(LTE_DL_FRAME_PARMS *frame_parms,uint32_t lte_gold_mbsfn_khz_1dot25_table[10][150],uint16_t Nid_mbsfn){
+  unsigned char sfn,l;
+  unsigned int n,x1,x2;//,x1tmp,x2tmp;
+
+  for (sfn=0; sfn<10; sfn++) {
+    x2 = (Nid_mbsfn) + (((1+(Nid_mbsfn<<1))*(1 + (7*(1+sfn))))<<9); //cinit
+    x1 = 1+ (1<<31);
+    x2=x2 ^ ((x2 ^ (x2>>1) ^ (x2>>2) ^ (x2>>3))<<31);
+    for (n=1; n<50; n++) {
+      x1 = (x1>>1) ^ (x1>>4);
+      x1 = x1 ^ (x1<<31) ^ (x1<<28);
+      x2 = (x2>>1) ^ (x2>>2) ^ (x2>>3) ^ (x2>>4);
+      x2 = x2 ^ (x2<<31) ^ (x2<<30) ^ (x2<<29) ^ (x2<<28);
+    }
+    for (n=0; n<150; n++) {
+      x1 = (x1>>1) ^ (x1>>4);
+      x1 = x1 ^ (x1<<31) ^ (x1<<28);
+      x2 = (x2>>1) ^ (x2>>2) ^ (x2>>3) ^ (x2>>4);
+      x2 = x2 ^ (x2<<31) ^ (x2<<30) ^ (x2<<29) ^ (x2<<28);
+      lte_gold_mbsfn_khz_1dot25_table[sfn][n] = x1^x2;
+    }
+  }
+}
+#endif
+
+
+
 #ifdef LTE_GOLD_MAIN
 main()
 {